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Abstract:

A ball injecting apparatus for releasing balls into a well comprises a
housing adapted to be supported by a wellhead structure, the housing
having an axial bore therethrough, said axial bore being in fluid
communication and aligned with the wellbore, at least one ball housing
having a radial bore extending away from the axial bore, a ball ram block
movable along the radial bore and having a chamber for storing a ball
therein or for releasing a ball therefrom, an actuator for moving the
ball ram block along the radial bore and an external port on the ball
housing for providing access to the ball ram block and the chamber.

Claims:

1. A ball injecting apparatus for releasing balls into a well having a
wellhead structure and wellbore comprising: a main housing adapted to be
supported by the wellhead structure, the main housing having an axial
bore therethrough, said axial bore being in fluid communication and
aligned with the wellbore; at least one ball housing having a radial bore
extending radially away from the axial bore and in fluid communication
therewith; for each ball housing, a ball ram block movable along the
radial bore, the ball ram block having a chamber for storing a ball
therein or releasing a ball therefrom; for each ram block, an actuator
for moving the ball ram block along the radial bore for operably aligning
said ball ram block with the axial bore for releasing any stored ball
therein into said axial bore and operably misaligning said ball ram block
from the axial bore for clearing the axial bore; and an external port on
said ball housing for providing access to the ball ram block and the
chamber.

2. The ball injecting apparatus of claim 1, wherein the external port
further comprises: a passage through the ball housing to guide a ball
into the chamber when said ram ball block is in a misaligned position;
and means to selectively seal the external port so as to retain fluid
pressure in the ball housing or so as to provide access to the chamber.

3. The ball injecting apparatus of claim 2, wherein the external port has
a distal end and the means to selectively seal the external port
comprises a closing member that is removably, sealably secured at said
distal end.

4. The ball injecting apparatus of claim 3, wherein the closing member
comprises a plug sealably secured at the distal end by means of a quick
release union.

6. The ball injecting apparatus of claim 2, wherein the passage is
oriented substantially parallel to the axial bore.

7. The ball injecting apparatus of claim 2, wherein the passage is
oriented at an angle anywhere between 10 to 80 degrees up from the
horizontal plane.

8. The ball injecting apparatus of claim 2, wherein the passage is
oriented at an angle approximately 40 degrees up from the horizontal
plane.

9. The ball injecting apparatus of claims 1 to 8, wherein the chamber
comprises entrance and exit openings of sufficient dimensions to provide
sufficient clearance to a ball to allow said ball to enter or exit easily
through either of said entrance or exit opening.

10. The ball injecting apparatus of claims 1 to 9, further comprising an
indicator system to provide confirmation of alignment of the ball ram
block with the axial bore.

11. The ball injecting apparatus of claim 10 wherein the indicator system
further comprises: an indicator housing having an indicator viewing
window; and an indicator rod moveable within said indicator housing and
viewable through said indicator viewing windows; wherein the indicator
rod is operably connected to the actuator.

12. The ball injecting apparatus of claims 1 to 11, wherein the ram ball
block further comprises a radial bore cap biased outward so as to align
substantially with the wall of axial bore when the ram block is retracted
within the radial bore into a misaligned position.

13. The ball injecting apparatus of claims 1 to 12, wherein the ram ball
block further comprises rotational alignment means to prevent rotation of
the ram block 11 relative to the ball housing.

14. The ball injecting apparatus of claims 1 to 13, comprising a
plurality of ball housings arranged into at least one radial ball array.

15. The ball injecting apparatus of claim 14, wherein the plurality of
ball housings comprise three radial ball arrays stacked vertically on top
of one another, each array having four ball housings, each with their
respective radial bores oriented at 90 degrees from one another.

16. The ball injecting apparatus of claim 14, wherein the plurality of
ball housings comprise two radial ball arrays stacked vertically on top
of one another, each array having four ball housings, each with their
respective radial bores oriented at 90 degrees from one another.

17. A ball injecting apparatus for releasing balls into a well having a
wellhead structure and wellbore comprising: a main housing adapted to be
supported by the wellhead structure, the main housing having an axial
bore therethrough, said axial bore being in fluid communication and
aligned with the wellbore; at least one ball housing having a radial bore
extending radially away from the axial bore and in fluid communication
therewith; for each ball housing, a ball ram block movable along the
radial bore, the ball ram block having a chamber for storing a ball
therein or releasing a ball therefrom; and for each ram block, an
actuator for moving the ball ram block along the radial bore for operably
aligning said ball ram block with the axial bore for releasing any stored
ball therein into said axial bore and operably misaligning said ball ram
block from the axial bore for clearing the axial bore; wherein the
chamber comprises entrance and exit openings of sufficient dimensions to
provide sufficient clearance to a ball to allow said ball to enter or
exit easily through either of said entrance or exit opening.

18. The ball injecting apparatus of claim 17, wherein the ram ball block
further comprises a radial bore cap biased outward so as to align
substantially with the wall of axial bore when the ram block is retracted
within the radial bore into a misaligned position.

19. A ball housing with actuator assembly for use with a ball injecting
apparatus, said ball injecting apparatus for releasing balls into a well
having a wellhead structure and wellbore and having a main housing
adapted to be supported by the wellhead structure, the main housing
having an axial bore therethrough, said axial bore being in fluid
communication and aligned with the wellbore, the ball housing assembly
comprising: a radial bore extending radially away from the axial bore and
in fluid communication therewith; a ball ram block movable along the
radial bore, the ball ram block having a chamber for storing a ball
therein or releasing a ball therefrom; an actuator for moving the ball
ram block along the radial bore for operably aligning said ball ram block
with the axial bore for releasing any stored ball therein into said axial
bore and operably misaligning said ball ram block from the axial bore for
clearing the axial bore; and an external port on said ball housing for
providing access to the ball ram block and the chamber.

20. The ball housing with actuator assembly of claim 19, wherein the
external port further comprises: a passage through the ball housing to
guide a ball into the chamber when said ram ball block is in a misaligned
position; and means to selectively seal the external port so as to retain
fluid pressure in the ball housing or so as to provide access to the
chamber.

Description:

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a regular application of U.S. Provisional
Patent Application Ser. No. 61/508,590 filed Jul. 15, 2011 and entitled,
"BALL INJECTING APPARATUS FOR WELLBORE OPERATIONS WITH EXTERNAL LOADING
PORT", the entirety of which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to an apparatus that houses, and
controls the release of, down-hole actuating devices for oil and gas
wells. More particularly, the apparatus comprises one or more external
loading ports to introduce or inject actuating devices into the apparatus
and provides positive identification as to whether a particular actuating
device was successfully injected into the wellbore.

BACKGROUND OF THE INVENTION

[0003] Down-hole actuating devices serve various purposes. Down-hole
actuating devices such as balls, darts, etc. may be released into a
wellhead to actuate various down-hole systems.

[0004] For example, in an oil well fracturing (also known as "fracing") or
other stimulation procedures the down-hole actuating devices are a series
of increasingly larger balls that cooperate with a series of packers
inserted into the wellbore, each of the packers located at intervals
suitable for isolating one zone of interest (or intervals within a zone)
from an adjacent zone. Isolated zone are created by selectively engaging
one or more of the packers by releasing the different sized balls at
predetermined times. These balls typically range in diameter from a
smallest ball, suitable to block the most downhole packer, to the largest
diameter, suitable for blocking the most uphole packer.

[0005] At surface, the wellbore is normally fit with a wellhead including
valves and a pipeline connection block, such as a frachead, which
provides fluid connections for introducing stimulation fluids, including
sand, gels and acid treatments, into the wellbore.

[0006] Conventionally, operators introduce balls to the wellbore through
an auxiliary line, coupled through a valve, to the wellhead. This
auxiliary line would be fit with a valved tee or T-configuration
connecting the wellhead to a fluid pumping source and to a ball
introduction valve. One such conventional apparatus is that as set forth
in U.S. Pat. No. 4,132,243 to Kuus. There, same-sized balls are used for
sealing perforations and these are fed, one by one, from a stack of
identically sized balls held in a magazine.

[0007] However, the apparatus appears limited to using identically-sized
balls in the magazine stack during a particular operation. To accommodate
a set of balls of a different size, however, the apparatus of Kuus
requires disassembly, substitution of various components (such as the
magazine, ejector and ejector sleeve, which are properly sized for the
new set of balls) and then reassembly. The apparatus of Kuus, therefore,
cannot accommodate different sized balls during a particular operation,
since it is designed to handle only a plurality of same-sized sealer
balls at any one time. To use a plurality of different sized balls, in
the magazine, will result in jamming of the devices (such as in the
ejector sleeve area).

[0008] Moreover, the ball retainer springs in Kuus do not appear to be
very durable and would also need to be replaced when using a ball of a
significantly different size. There is a further concern that the ball
retainer springs could also break or come loss and then enter into the
wellbore (which is undesirable). Additionally, there is no positive
identification whether a ball was successfully indexed or ejected from
the stack of balls for injection.

[0009] Furthermore, the device of Kuus is oriented so as to have the
sealer balls transferred into the magazine by gravity and must therefore
utilize a fluid flow line and valved tee through which well treating
fluid and sealer balls are subsequently pumped into a wellbore. The
device of Kuus, with its peculiar orientations of components, could
therefore not be directly aligned with, or supported by, a wellhead.

[0010] More recent advance in ball injecting apparatus do feature a
housing adapted to be supported by the wellhead. Typically the housing
has an axial bore therethrough and is in fluid communication and aligned
with the wellbore. This direct aligned connection to the wellhead avoids
the conventional manner of introduce balls to the wellbore through an
auxiliary fluid flow line (which is then subsequently connected to the
wellhead) and the disadvantages associated therewith. Some of these
disadvantages, associated with conventional T-connected ball injectors,
include requiring personnel to work in close proximity to the treatment
lines through which fluid and balls are pumped at high pressures and
rates (which is hazardous), having valves malfunctioning and balls
becoming stuck and not being pumped downhole and being limited to smaller
diameter balls. In particular, larger packer balls also require specialty
large bore launchers and related 4'' and even 5'' piping which is costly,
may not have the required pressure ratings or, if so, be heavy and bulky.

[0011] Examples of more recent ball injecting apparatus, which are
supported by the wellhead, and are aligned with the wellbore, include
those described in published U.S. Patent Application 2008/0223587,
published on Sep. 18, 2008 and published U.S. Patent Application
2010/0288496, published on Nov. 18, 2010, the entirety of both published
applications being incorporated by reference herein. Another example of a
ball injecting apparatus supported by the wellhead and aligned with the
wellbore is published U.S. Patent Application 2010/0294511, published on
Nov. 25, 2010, the entirety of which is also incorporated by reference
herein. Although these devices address many of the above issues
identified with injection balls indirectly into the wellbore, i.e. via
fluid flow lines, these still retain a significant number of
disadvantages.

[0012] For example, it is know that the device taught in published U.S.
Patent Application 2010/0294511, where each ball is temporarily supported
by a rod or finger within the main bore. However, the pumping of
displacement fluid through unit can damage or scar balls, especially if
the displacement fluid is sand-laden fracturing fluid or if the balls are
caused to rapidly spin on the support rod or finger. Such damaged balls
typically fail to then properly actuate a downhole packer and fully
isolate the intended zone. This then requires an operator to drop an
identical ball down the bore which is extremely inefficient, time
consuming, costly and can adversely compromise the well treatment.

[0013] The apparatus described in published U.S. Patent Application
2008/0223587, published on Sep. 18, 2008 teaches a ball magazine adapted
for storing balls, in two or more transverse ball chambers, axially
movable in a transverse port and which can be serially actuated for
serially injecting the stored balls from the magazine into the wellbore.
This overcomes a number of the disadvantages of the device taught in
published U.S. Patent Application 2010/0294511. However, the invention
contemplates loading the magazine externally from the ball injecting
apparatus and, since the transverse chambers are transverse, cylindrical
passageways or bores through the magazine's body with both horizontal and
vertical openings, the plurality of balls can easily fall out of their
respective chambers during preloading operations (i.e. through either
entrance or exit openings). This could result in runaway balls on the
surface next to the wellhead and potentially create a safety hazard. The
design of this devices therefore makes the loading of the magazine
difficult and time consuming, especially when loading a magazine with a
large number of balls that must be monitored (i.e. to prevent the balls
from exiting out through their respective entrance or exit openings)
until placed within the axial bore of the apparatus.

[0014] Moreover, because the balls are serially positioned in a linear
extending magazine, the ball injector of this patent application becomes
cumbersome and unwieldy, especially when designed to work with 10, 12 or
even 24 balls. For all practical purposes, the apparatus of this
application is therefore limited to handling 5, or maybe 6, balls before
becoming ungainly and unmanageable. As such, the applicant in a
subsequent patent application, stated that this (earlier) apparatus
retains a measure of mechanical complexity.

[0015] Published U.S. Patent Application 2010/0288496, published on Nov.
18, 2010, teaches a radial ball injection apparatus comprising a housing
adapted to be supported by the wellhead. The housing has an axial bore
therethrough and at least one radial ball array having two or more radial
bores extending radially away from the axial bore and in fluid
communication therewith, the axial bore being in fluid communication and
aligned with the wellbore. Each radial bore has a ball cartridge for
storing a ball and an actuator for moving the ball cartridge along the
radial bore. The actuator reciprocates the ball cartridge for operably
aligning with the axial bore for releasing the stored ball and operably
misaligning from the axial bore for clearing the axial bore. This patent
application also teaches that several of the radial ball arrays can be
arranged vertically within one housing, or one or more of the radial ball
arrays can be housed in a single housing and vertically by stacked one on
top of another for increasing the number of available balls. For example,
in one embodiment, it describes using an injector having two vertically
spaced arrays of four radial bores so as to drop eight (8) ball.

[0016] However, published U.S. Patent Application 2010/0288496 suffers
from a number of disadvantages including icing issues during winter
operations which can result in the balls being frozen within their
respective ball cartridges which have a cup-like body comprised of an
open side, a lateral restraining structure and a supporting side for
seating the ball during loading. However, during winter operations, the
balls can become frozen within this cup-like body, thereby preventing
proper release of the balls downhole. For that reason, U.S. Patent
Application 2010/0288496 teaches that one should use methanol in the
displacement fluid to reduce such icing issues. However, using methanol
adds to the expense and complexity of the ball injection process.

[0017] Moreover, and although U.S. Patent Application 2010/0288496 teaches
an indicator for indicating a relative position of the ball cartridge
between the aligned and misaligned positions, this indicator does not
indicate whether a ball was actually released from the cup-like
structure, when placed in the aligned position, or whether it remains
stuck and frozen within the ball cartridge, only to be retracted back
into the radial bore when returned to the misaligned position. Therefore
an operator of this apparatus cannot accurately determine whether a ball
was successfully released from the injector as taught in this patent
application.

[0018] A further disadvantage of the apparatus taught by U.S. Patent
Application 2010/0288496 is that each of the balls are loaded through the
axial bore of the injector by rotating the ball cartridge into a
receiving position and then aligning each ball cartridge with the axial
bore so as to be able receive a ball from above as it is dropped through
the axial bore. This results in a time consuming an awkward loading
procedure wherein balls are loaded serially, one after another, with each
ball cartridge then being stroked between misaligned, aligned and then
misaligned position. In an alternate loading procedure, this application
suggest to pre-load the apparatus by removing the ball cartridges from
each housing, seating the balls into each ball cartridge, and then
reinstalling the loaded ball cartridges on each radial housing. This
alternate loading procedure is also time consuming and awkward.

[0019] Additionally, in the primary suggested loading procedure, the balls
will need to be carefully aligned along the axial bore and above its
particular ball cartridge before being dropped, so as to avoid missing
the ball cartridge and then having the ball continue on downward the
axial bore. If a dropped ball does miss the intended ball cartridge and
continues downward the axial bore then, in a best case scenario such as
during pre-loading, the ball exits at the bottom end of the injector to
be simply retrieved and loading can then be attempted again. However, if
a dropped ball misses the intended ball cartridge when the injector is
mounted to the wellhead structure or above a gate valve, then the
injector will have to be disconnected from the wellhead or gate valve so
as to then retrieve the ball. In a worst case scenario, a ball that is
dropped in the axial bore and which misses the ball cartridge could
prematurely be launched down the wellbore and premature activate one or
more downhole tools (such as packers), resulting a ruined fracturing
operation. As such the application even teaches use of a calibrated
tubular or sleeve to assist with the loading of the balls through the
axial bore. This additional piece of equipment adds further complication
to the apparatus and loading procedure.

[0020] Another prior art apparatus that utilizes a housing having an axial
bore therethrough and a radial ball array having two radial bores
extending radially away from the axial bore and in fluid communication
therewith, the axial bore being in fluid communication and aligned with
the wellbore, is that taught by U.S. Pat. No. 5,960,881 to Allamon et al.
However, this apparatus is only designed to drop two balls (preferably
sized at 11/4'' for the smaller ball and a 1.75'' for the larger ball)
along with a drill pipe wiper dart and therefore is unsuitable to drop
more than two balls, such as 8 to 12 balls. Additionally, this apparatus
relies on elastomer members having specifically sized circular openings
to allow release of different sized balls when they are urged into the
axial bore by a rod and piston. This elastomer member is subject to
wearing down. Moreover, the different sized circular openings in the
elastomer, along with the need to utilize a centering member to properly
locate the smaller ball within the radial bores, makes this apparatus
complex and impractical for a multi-size and multi-ball application.

[0021] As such, there remains a need for a safe, simple and efficient
apparatus and mechanism for loading balls therein and for subsequent
introducing into a wellbore.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Embodiments of the invention will now be described, by way of
example only, with reference to the accompanying drawings, wherein:

[0023] FIG. 1a is perspective view of an embodiment of the invention;

[0024] FIG. 1 b is a side view of the embodiment of FIG. 1a;

[0025] FIG. 2a is a sectional view of the embodiment of FIG. 1a along line
A-A of FIG. 1b;

[0037]FIG. 7b is a side view of one of the ball housings with actuator
and indicator system of the embodiment of FIG. 6a;

[0038]FIG. 7c is a sectional view of the ball housing with actuator and
indicator system of the embodiment of FIG. 6a along line D-D of FIG. 7b;

[0039]FIG. 8a is a sectioned perspective view of the embodiment of FIG.
6a;

[0040]FIG. 8b is a perspective view of the ball housing with actuator and
indicator system of the embodiment of FIG. 6a, illustrating the ball ram
block in an extended, aligned position and illustrating the radial bore
cap in a compressed position;

[0041] FIGS. 9a-9g are perspective views of the embodiment of a ball ram
block and radial bore cap of the embodiment of FIG. 6a and illustrating
the radial bore cap in both compressed and extended positions;

[0042] FIGS. 10a-10c are sectioned perspective views of the ball housing
with actuator, ram block and indicator system of the embodiment of FIG.
6a, illustrating the ball ram block in an extended, aligned position and
illustrating the radial bore cap in a compressed position;

[0043] FIGS. 11a-11c are sectioned perspective views of the ball housing
with actuator, ram block and indicator system of the embodiment of FIG.
6a, illustrating the ball ram block in a retracted, misaligned position
and illustrating the radial bore cap in an extended position;

[0044] FIG. 12a is a perspective view of the ball ram block of FIGS.
9a-9g, but not showing the radial bore cap;

[0045] FIG. 12b is a sectioned perspective view of the ball ram block of
FIGS. 9a-9g, also illustrating a piston rod attached to the ram block and
showing the radial bore cap in an extended position;

[0046] FIG. 13 is perspective view of yet another embodiment of the
invention;

[0047] FIG. 14 is a side view of the embodiment of FIG. 13; and

[0048] FIG. 15 is a sectional view of the embodiment of FIG. 13.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] The following description is of a preferred embodiment by way of
example only and without limitation to the combination of features
necessary for carrying the invention into effect. Reference is to be had
to the Figures in which identical reference numbers identify similar
components. The drawing figures are not necessarily to scale and certain
features are shown in schematic or diagrammatic form in the interest of
clarity and conciseness.

[0050] With reference to the Figures, and generally in accordance with a
preferred embodiment of the invention as shown in FIGS. 6a-12b, the ball
injecting apparatus or injector 10 receives and releases balls 12,
including drop balls, frac balls, packer balls, and the like, down a
wellbore 20b to, for example, isolate zones of interest during wellbore
operations such as fracturing. The injector 10 is preferably supported on
a wellhead structure 20 connected to the wellbore 20b (see FIG. 6c).
Preferably, the injector 10 is fit with a top access port 10p and an
access valve 10v, such as a T-valve.

[0051] The wellhead structure 20 can include a high pressure wellhead or a
frac head and a wellhead valve 20v having a bore sufficiently large to
permit the passage of the balls 12 therethrough. In the context of
fracturing or treating sequential zones within a formation accessed by
the wellbore 20b, flow passage P is fluidly connected to the wellbore 20b
through the wellhead 20. The wellhead 20 may be connected to pump trucks
(not shown) through a fluid line (not shown) for supplying a fracturing
or stimulation fluid to the wellbore 20b in a conventional manner, such
as through the injecting apparatus 10 or through other ports in the
wellhead 20 at a point below the injecting apparatus 10.

[0052] The ball injector 10 comprises a main housing 30 having an axial
bore 32. The axial bore 32 is in fluid communication and aligned with the
wellbore 20b and flow passage P. The ball injector 10 further comprises
at least one ball housing 34 having a radial bore 33 and a ball ram block
11. Ball ram block 11 is adapted to store a range of diameters of balls,
up to the largest ball required for the particular operation. Ball ram
block 11 is preferably preloaded with said ball 12 and is movable along
the radial bore 33 for aligning the ball 12 with the axial bore 32 and
flow passage P so as to effect injection of said ball 12 into the
wellbore 20b (see, for example, FIGS. 2a-2b, 8a, 10a-10c and 11a-11c). In
a preferred embodiment, axial bore 32 has a diameter of 7 and 1/16
inches.

[0053] Preferably, the ball injector 10 is fit with at least one radial
ball array 35 comprised of two or more ball housings 34, wherein each of
the radial bores 33 of the two or more ball housings 34 are in fluid
communication with the axial bore 32, for selectively making two or more
balls 12 available to the axial bore 32. The embodiments illustrated in
FIGS. 1a-12b show a ball injector 10 comprised of three radial ball
arrays 35 stacked vertically on top of one another, each array 35 having
four ball housings 34, each with radial bores 33 oriented at 90 degrees
from one another (the bores 33 in each array 35 being along the same
horizontal plane), for a total of twelve ball housings 34. The embodiment
illustrated in FIGS. 13-15 shows a ball injector 10 comprised of two
radial ball arrays 35 stacked vertically on top of one another, each
array 35 having four ball housings 34, each with radial bores 33 oriented
at 90 degrees from one another (along the horizontal plane), for a total
of eight ball housings 34.

[0054] Advantageously, by placing two, three, four or more ball housings
34 in the same radial ball array 35, significant height savings are
achieved. More advantageously, a lower profile of the ball injector 10
allows for easier access to the injector 10 as well as reduces the strain
applied to the entire wellhead 20. Moment forces imposed on the wellhead
can be considerable and thus a shorter wellhead is stronger and safer.

[0055] Ball ram block 11 maintains ball 12 in the radial bore 33 and may
be actuated to reciprocate, extending into and in operable alignment with
the axial bore 32 for releasing a ball 12. Ball ram block 11 may also be
actuated to retract into the radial bore 33 for operable misalignment
with the axial bore 32 for clearing the axial bore 32 and for storing and
preventing a ball 12 from being prematurely released or launched into the
wellbore 20b. For example, see FIGS. 2a-2b, 8a and 15.

[0056] Balls 12 can be injecting directly into the wellhead 20 by gravity
or fluid which urges the balls 12 from the ball ram block 11 (when in
operable alignment with axial bore 32) and into the flow passage P. In
many instances, a flow of fluids F is introduced through flow passage P
or other ports in the wellhead to the wellbore 2 therebelow. By injecting
the ball 8 directly into the flow passage P to join the flow fluid F one
avoids accidental lodging of the ball 8 in side ports or other cavities
such as in some prior art T-configuration injection apparatus.
Advantageously, the ball 12 does not need to change direction and is
reliably introduced into the flow of fluids F through the wellhead 20 for
delivery down the wellbore 20b.

[0057] The ball ram block 11 comprises a piston-like linearly-extending
body 11b having at least one chamber 40 to receive, store and discharge
an individual ball 12. Body 11b has at least constraining end walls 40c,
40d for forming the chamber 40 and for retaining the ball within the ball
ram block 11 during reciprocating movement along the radial bore 33.
Preferably chamber 40 is a transverse, substantially cylindrical
passageway or bore through the body 11b, for forming entrance and exit
openings 40a, 40b to permit ball 12 to be loaded into the chamber 40 or
released therefrom. More preferably, entrance and exit openings 40a, 40b
are of sufficient dimensions to provide sufficient clearance to ball 12
so as to allow it to enter or exit easily through either opening and in
either direction.

[0058] When a selected chamber 40 is axially aligned with the axial bore
32, it is fluidly contiguous with the flow passage P to allow egress of a
ball 12 from the chamber 40 into the wellbore 20b via axial bore 32 and
flow passage P. Preferably, the chamber 40 and the apparatus 10 itself
can be sized to accept a range of diameters of balls up to the largest
ball required for the particular operation.

[0059] Advantageously, by virtue of transverse chamber 40, ball ram block
11 does not result in a cup-like structure or cartridge (as is the case
in U.S. Patent Application 2010/0288496) and therefore does not suffer
from the same disadvantages associated with such a cup-like structure
(i.e. balls 12 do not become frozen within ram block 11 and methanol is
not needed to reduce icing issues; since no icing issues occur with the
present invention).

[0060] To provide access to a ram block 11, when the ball ram block 11 is
within the radial bore 33, the ball housing 34 and radial bore 33 are
provided with an external port 50. External port 50 comprises a passage
50p through the ball housing 34, said passage 50p being of suitable
dimensions to accept a range of diameters of balls, up to the largest
ball required for the particular operation, and guide such balls 12 into
the chamber 40 of a ram block 11 when said block 11 is in the misaligned
position MP. The external port 50 is selectively sealable at its distal
end 50d, so as to retain fluid pressure in the ball housing 34 (and hence
also axial bore 32 and flow passage P) or so as to provide access to the
chamber 40 (for loading, unloading or inspection of ball 12 therein) as
may be desired during operations.

[0061] Preferably, external port 50 is selectively sealable by using a
closing member 52 that is removably, sealably secured at distal end 50d.
More preferably, closing member 52 comprises a plug 52p sealably secured
at distal end 50d by means of a quick release union such as a hammer
union assembly 52h, thereby permitting easy access to the passage 50p,
the radial bore 33 and the ball ram block 11 to remove, load and replace
a ball 12 in the chamber 40. Alternatively the external port 50 may be
sealably secured within the ball housing 34 using other releasable
connections. Preferably, the apparatus 10 is designed to American
Petroleum Institute (API) standards for the particular design criteria
including pressure and fluid characteristics. More preferably, the
apparatus 10 is rated for 10,000 psi.

[0062] In the embodiment of FIGS. 1a-2b, the external port 50 is located
within a lateral extension 34l of the ball housing 34 and the axis of its
passage 50p is oriented substantially along the vertical axis (and
substantially parallel to the axial bore 32). In this embodiment
sufficient space or clearance SP is provided between adjacent ball
housings 34 (which may be overlapping in their respective radial ball
arrays 35) so as to allow for loading and unloading of balls 12 in all of
the ball housings 34 that may be present in the apparatus 10 (see FIG. 1
b). In the embodiments of FIGS. 3a-4c, 6a-12b and 13-15, the external
port 50 is likewise located within a lateral extension 34l of the ball
housing 34, but its passage 50p is oriented (along with ball housing 34)
at a slanted angle relative the vertical axis or axial bore 32.
Preferably, this angle is approximately 40 degrees up from the horizontal
plane (see FIG. 6b, angle between lines E and E'). Other slanted angles
(not shown), such as anywhere in the range of 10 to 80 degrees up from
the horizontal plane, would likewise work.

[0063] In embodiments where the slanted angles are below the horizontal
plane (not shown), i.e. where the external port's passage opening faces
downward, gravity will tend to pull any ball 12 out of the ram block 11
(and ball housing 34), thereby making loading or checking of the ball 12
more difficult than when the slanted angle is above the horizontal plane
and gravity assists in keeping the ball 12 within chamber 40 and radial
bore 33. In such embodiments, reliance will have to be placed on the
closing member 52 to maintain the ball 12 in the proper position within
the ram block's chamber 40 and sufficient clearance of the various
components will need to be provided so that actuation of the apparatus 10
into the aligned position OA does not result in interference or jamming
of some of the apparatus' components (e.g. plug 52p component of closing
member 52 is of sufficient dimension to still retain ball 12 within the
chamber 40, but is not too long so as to jam the ram block 11 when it is
actuated to the aligned position OA).

[0064] Advantageously, this slanted angle of the external port 50 and ball
housing 34 between 10 to 80 degrees up from the horizontal plane, along
with the four radial bores 33 in each array 35 being oriented at 90
degrees from one another, allows for a closer spacing SP' of each array
35 to an adjacent array 35 while still providing sufficient clearance to
load, unload and view balls 12 through the external port 50. See, for
example, FIGS. 6a-6b and FIGS. 13-14. More advantageously, a slanted
angle of the external port 50 and ball housing 34, between 10 to 80
degrees up from the horizontal plane, provides from a more natural and
easier viewing angle to an operator when the apparatus 10 is placed high
up on a wellhead structure 20 and a particular ball housing 34 and ram
block 11 needs to be inspected.

[0065] An actuator 14 is provided to the ball housing 34 for positioning
the ball ram block 11 for aligning a ball 12 (held within a chamber 40)
with the axial bore 32 and flow passage P and assuring injection of the
ball 12 out of a chamber 40 and into the wellbore 20b. The ball ram block
11 is actuated reciprocally axially within the radial bore 33 by the
actuator 14 between an operably aligned position OA and an operably
misaligned position MP. As shown in FIGS. 8a, 8b and 10a-10c, as well as
in the embodiments of FIGS. 2a-2b and FIG. 15, when placed in an operably
aligned position OA, the ball ram block 11 is located within the axial
bore 32 for releasing a ball 12 into the wellbore 20b. As shown in FIGS.
7b-7c, 8a and 11a-11c, as well as in the embodiments of FIGS. 2a-2b and
FIG. 15, when in the misaligned position MP, the ball ram block 11 is
retracted into its respective radial bore 33, fully clearing the axial
bore 32 and either safely housing the ball 12 from accidental release
into the axial bore 32 or having empty chamber 40.

[0066] The ball ram block 11 itself, and the actuation thereof, is
insensitive to the size of the balls. A suitable actuator 14 is a
conventional double-acting hydraulic ram 60 having a piston 61 in a
cylinder 62. See, for example, FIG. 7c. The piston 61 is operatively
connected to the ball ram block 11, such as through a piston rod 63. A
piston rod seal or seals 48 are positioned between the ball housing 34
and the piston rod 63 wherein the radial bore 33 and wellbore 20b are
contained and further are isolated from the actuator 11. Ports 64 are
provided at opposing ends 65, 66 of the cylinder 62 for connection to a
control valve (not illustrated) as understood by one of skill in the art,
and which can be actuated remotely.

[0067] In embodiments of the invention, rotational alignment means 80 are
provided for ensuring that the ball ram block 11, having chambers 40
formed therein, remains rotationally oriented during axial manipulation
of the ram block 11 for aligning of the chamber 40 with the axial bore
32. While the radial bore 33 in ball housing 34 and ram block 11 can have
a cross-sectional profile which resists rotation, such as a corresponding
polygonal profile, pressure conditions of the wellbore 20b encourage
selection of a generally cylindrical housing 34 and ram block 11.
Accordingly, means 80 are provided for preventing rotation of the ram
block 11 relative to the ball housing 34. One of skill in the art would
appreciate that alignment of the ram block 11 within the ball housing 34
may be accomplished in a number of different ways including the use of
alignment pins, splines, key and keyway combinations, locking nuts and
the like.

[0068] As shown in FIGS. 10a-11c and in the preferred embodiment of the
invention, the ball ram block 11 is aligned within the ball housing 34,
and so as to retain proper alignment of the chamber 40 throughout the
axial manipulation of the ball ram block 11, via alignment pin 82
attached within ball housing 34. As shown, the pin 82 is mounted at end
34e of the interior of the ball housing 34 and matching keyway or pin
chamber 84 is formed in the ball housing 11 for sliding movement along
pin 82 when actuated.

[0069] Preferably, an indicator system 100 is provided for confirmation of
alignment of a ball ram block 11 with the axial bore 32 and flow passage
P, in the aligned position OA, so as to ensure a ball 12 is injected when
required. The indicator system 100 may comprise an indicator rod 105
extending from an end 65 of the actuator 14 opposite the hydraulic ram 60
and connected to piston 61 for movement therealong with. In the
embodiment of FIGS. 6a-12b, the indicator rod 105 extends through an
indicator housing 107 which includes indicator viewing windows or
openings 108 aligned axially along the housing 107, to allow viewing of
the indicator's position therethrough. Preferably, indicator rod 105 is
painted a bright colour so as to provide a quick and easy visual cue to
allow an operator to determine the indicator's, and the ball ram block's,
relative axial position. Indicator rod seal 110 and indicator housing
seals 111 are provided at the appropriate places in a conventional manner
so as to contain wellbore pressure within the injector 10 and ball
housing 34. See, for example, FIG. 7c.

[0070] In a preferred embodiment, and as more clearly shown in FIGS.
9a-9g, the ram block 11 is provided with a radial bore cap 120 at the end
11e of the ram block 11 that is proximal to the axial bore 32. More
preferably, radial bore cap 120 is housed within a cavity 11c of the ram
block 11 at proximal end 11e. Even more preferably, radial bore cap 120
is biased outward, in a normally expanded state, by a spring 124 placed
within cavity 11c and a second cavity 126 that is within the radial bore
cap 120 (see FIGS. 7c, 8a, 9f-9g and 15). The amount of outward biasing
of radial bore cap 120 relative to the ram block 11 by spring 124 is
pre-set, and the cap 120 is sufficiently retained within the ram block 11
when biased outward, so that radial bore cap 120 aligns substantially
with the wall of axial bore 32 when the ram block 11 is retracted within
the radial bore 33 into the misaligned position MP (see FIG. 8a for
example). One of skill in the art would appreciate that retaining the
bore cap 120 and preventing it from completely disengaging from the ram
block 11 may be accomplished in a number of different ways including the
use of alignment pins, splines, key and keyway combinations, and the
like.

[0071] Advantageously, radial bore cap 120 prevents accidental lodgment of
a ball 12 (that may have been inserted into axial bore 32 by another ball
housing 34) within said radial bore 33 and thereby encourages such ball
12 to instead travel down the axial bore 32 into the wellbore 20b. More
advantageously, should a first ram block 11 be in the misaligned position
MP and a second ram block 11, located directly opposite the first ram
block 11 in the same radial ball array 35, is then actuated to the
aligned position OA, radial bore caps 120 of both ram blocks 11 will abut
and be placed in a compressed state, thereby allowing the second ram
block 11 to partially enter the radial bore 33 of the first ram block 11.
Even more advantageously, the use of such spring-biased radial bore caps
120 allows for optimal axial bore diameters while still providing for
large radial bore diameters (capable of holding larger balls 12) and a
radial ball array 35 having four ball housings 34 located at 90 degrees
from each other along the horizontal plane of said array 35.

[0072] Operation

[0073] Preferably, an injector 10 having at least one radial ball array 35
with two or more radial bores 33, each having an associated ball housings
34 with an actuator 14, is provided. However, it is contemplated that an
embodiment of the injector 10 comprises only a single radial bore 33 and
a single ball housing 34 with an actuator 14 (and therefore no radial
array). Multiple ball 12 drops would then be accomplished through
repeated reloading of the chamber 40 through the external port 50 as
further described herein.

[0074] In a preferred embodiment, and during normal fracturing operations,
an injector having said at least one radial ball array 35 is provided
wherein the ball ram blocks 11 are normally positioned in the misaligned
position MP within the radial bores 33, each storing a ball 12. Thus, an
open and unobstructed axial bore 32 allows an operator to have unhindered
access to the wellbore 20b during normal wellbore or fracturing
operations. Preferably, there are at least as many radial bores 34 and
ball housings 34 as there are balls 12 required for a particular wellbore
operation. For example, in the embodiment of FIGS. 6a-12b, the injector
10 has three radial ball arrays 35, each array 35 having four radial
bores 33 and corresponding ball housings 34, providing for a total of
twelve balls 12. As another example, the embodiment of FIGS. 13-15, the
injector 10 has two radial ball arrays 35, each array 35 having four
radial bores 33 and corresponding ball housings 34, providing for a total
of eight balls.

[0075] At the appropriate times and as operations dictate, each ball ram
block 11 is sequentially actuated by actuator 14, one by one, to the
operably aligned position OA for release and injection into the wellbore
20b. Preferably this alignment is confirmed by the indicator system 100
for each particular ball ram block 11. Once in the aligned position OA,
the ball 12 will be released from the chamber 40, under the influence of
gravity, into the axial bore 32 and to the wellbore 20b via flow passage
P. Alternatively ball 12 can be positively displaced from the chamber 40
by fluid (such as fracturing fluid) that may be moving through the flow
passage P.

[0076] In situations where a very large number of balls 12 are required to
be dropped, one or more of the chambers 40 in a ball housing 34 may be
reloaded with a subsequent ball 12 via external port 50. This may be
accomplished by isolating the injector 10 from wellbore pressures (such
as by closing wellhead valve 20v and then bleeding off the pressure
through top access port 10p and access valve 10v), unsealing the external
port 50 (such as by removing closing member 52), ensuring the ram block
11 is actuated to the misaligned position MP and then loading said
subsequent ball 12 via external port 50. Advantageously, the injector 10
need not be removed from the wellhead structure 20 in order to reload
balls.

[0077] Likewise, a similar procedure can be used to retract a ram block 11
into the misaligned position MP, open and unseal the external port 50 so
as to provide an operator with a visual view into the ram block 11 and
chamber 40, such as to ensure that a ball 12 has left its chamber 40.
Advantageously, if there was any doubt about a particular ball 12 having
been successfully released into the wellbore 20b, such quick means to
obtain a visual view into the chamber 40 can provide additional
confirmation of such release or of an unsuccessful attempt.

[0078] Embodiments of the invention are discussed herein in the context of
the actuation of a series of packers within a wellbore for isolating
subsequent zones within the formation for fracturing of the zones. A
series of packers typically use a series of different sized balls for
sequential blocking of adjacent packers. One of skill in the art however
would appreciate that the invention is applicable to any operation
requiring the dropping of one or more balls (whether same-sized or
different sized) into the wellbore.

Patent applications in class With means for injecting solid or particulate material into the well

Patent applications in all subclasses With means for injecting solid or particulate material into the well